Manufacturing of semiconductor devices typically involves performing a sequence of procedures with respect to a substrate such as a silicon substrate, a glass plate, etc. (Such substrates may also be referred to as wafers, whether patterned or unpatterned.) These steps may include polishing, deposition, etching, photolithography, heat treatment, and so forth. Usually a number of different processing steps may be performed in a single processing system or “tool” which includes a plurality of processing chambers. However, it is generally the case that other processes are required to be performed at other processing locations within a fabrication facility, and it is accordingly necessary that substrates be transported within the fabrication facility from one processing location to another. Depending upon the type of semiconductor device to be manufactured, there may be a relatively large number of processing steps required to be performed at many different processing locations within the fabrication facility.
It is conventional to transport substrates from one processing location to another within substrate carriers such as sealed pods, cassettes, containers and so forth. To prevent damage to substrates transported within substrate carriers, care should be taken to ensure that substrates are not contaminated during transport with the substrate carriers. Methods and apparatus for reducing the contamination of substrates within a substrate carrier are desired.